Having the nipple stick up above the oil level sure makes sense to me. I also found a "Complete ballast kit" P/N 61-8005B for $67.08 in the long list of replacement parts at the Welch site. Right in with the other bits and pieces of the gas ballast valve.
Another thought occurs here.. If a drilled orifice is used, a little bit of Swagelok Hdw with a Whitey valve would probably do the trick. Would not be much cheaper if all the hdw was bought new, but if you have it lying around, could be the short way to a ballast. I have a Whitey Needle Valve...that I use now for the gas bleed to dry an evap chamber. I will try that and report. You could also use a machined nipple with the bolt thd on one end and tapped for 1/4" NPT female on the outboard end to make up to a valve of some sort. Guessing that the bleed hole wants to be less than 1mm dia, perhaps 0.5 mm, that's about a #75 drill.
Dave Cooper
Created on Wednesday, April 11, 2001 3:15 AM EDT by David Cooper